Many food and drug substances destined for human consumption are distributed within containers Unfortunately, situations have occurred where the contents of the container have been adulterated by unauthorized entry into the container without indication to the consumer that the container has been entered. Often, this tampering leads to death or serious harm to the consumer and in order to reduce the risk of a consumer ingesting an adulterated dosage means have been developed for indicating if tampering has occurred.
A typical example of a tamper-proof seal incorporated with a container includes surrounding the container with a cellophane or clear plastic wrapping However, the plastic might be completely removed and subsequently replaced with no knowledge thereof being conveyed to the consumer.
Other attempts of containers incorporating tamper-proof means include affixing pliable material containing chemical substances to portions of the container where pressure must be applied for entry. The material may change color from either absorbing chemicals released by pressure applied to the container during opening, or from ambient atmosphere conditions exposed to the material during opening. Typical examples of such tamper-proof seals are shown in U.S. Pat. No. 4,424,911 and 4,511,052. Another container incorporating tamper-proof means is shown in U.S. Pat. No. 4,516,679 which includes a wrap for encasing a container whereby visual indication of a tampering by a wrap discoloration, physical change, or deterioration alerts the user that the product within the wrap may have been adulterated.
Tamper-proofing means of the aforementioned type undergo color change through chemical reactions requiring chemical substances that in addition to adding to the manufacturing cost of the product may unknowingly come in contact with the contents of the container, thus making the tamper-proof seal itself a health risk to the consumer.
It is an object of the invention to provide a reliable tamper-proof seal to be employed with drug or food filled containers by which to warn of possible unauthorized tampering with the container or contents thereof.
Another object of the invention is to provide a reliable tamper-proof seal to be employed with a drug or food filled container wherein the seal itself is manufacturable at low cost and is free of substances that might be harmful to the consumer.
Yet another object of the invention is to provide a reliable tamper-proof seal to be employed with a drug or food filled container that includes a plurality of cells filled with a harmless visible substance, whereby the substance is released from cells during entry, or attempted entry into the container.
A further object of the invention is to provide a reliable tamper-proof seal that includes a plurality of substance filled cells, wherein the cells are soluble in hot water such that upon submerging the seal in hot water the substance is released
Another object of the invention is to provide a reliable tamper-proof seal that would provide a visual indication of possible tampering from pressure applied to the seal or from a puncture therethrough even if such puncture is as small as that would be made by a hypodermic needle.
In the practice of the invention the tamper-proof seal is employed with a container and comprises a strip of plastic material having a plurality of frangible cells filled with a substance such as food coloring or dye formed thereon In one version of the invention the seal is located on a portion of the container where force must be applied for entry which breaks the cells releasing the substance to provide visual indication of possible tampering. The seal is provided with releasable means for authorized removal of the seal permitting entry into the container without rupturing the cells. In another embodiment the cells are located between two sheets of plastic, at least one being transparent, hermetically sealed around the outer edges providing a vacuum therebetween. The seal is affixed over the container opening sealing off the container and a cap or lid may be placed over the seal. Upon puncture or pressure being applied to the seal for entry into the container, even by an object as small as a hypodermic needle, the cells rupture releasing the dye between the sheets, whereby the released dye is readily visible detected through the transparent sheet for visually indicating that the container may have been adulterated. In both embodiments, the dye or substance contained in the cells is harmless to the consumer and upon the cells rupturing the substance is merely released to provide visual means to the consumer that the container may have been tampered.